Bleaching process.



s-iii Freezes DRAFT STATES PATENT OFFICE.

EUGENE L. MAUPAI, OF NEW YORK, N. Y.

BLEAGI-IING PROCESS.

No Drawing.

Patented July 9, 1912. Serial N 0. 689,627.

To all whom it may concern: I

Be it known that I, EUGENE L. MAUPAI,21, citizen of the United States of America, residing at Bronx borough, city, county, and State of New York, have invented certain new and useful Improvements in Bleaching Processes, of which the following is a full, clear, and exact description.

My invention relates to a new and improved process of bleaching vegetable fibrous material, such as cotton, linen and the like, including also artificial silk, the object of my process being to produce more effective bleaching in a more economical manner than has heretofore been done and in a shorter space of time.

I find that heretofore, when fabrics or fibrous material have already been dyed in colors, it has been diflicult if not impossible, to eliminate the dye and change the material or fibers into their natural undyed or bleached condition, and one of the objects of my invention is to provide an efficient and economical process for producing this effect, besides the bleaching of undyed fibrous material into a pure white.

In carrying out my improved process, if I desire, for instance, to bleach fibrous cotton or linen from its natural condition to a pure white, I place a sufficient quantity, say 100 pounds, of such cotton in a bath of cold water, having previously added to the water three per cent. (of the weight of the cotton) of permanganate of potassium, together with one to two per cent. (of the weight of the cotton).of sulfuric acid, and allow the cotton to soak for about one-half an hour. I thereupon immerse the cotton in a fresh water bath containing two and one-half per cent. (of the weight of the cotton) 1 of sodium nitrite and three per cent. (of the weight of the cotton) of sulfuric acid. I'allow the cotton to remain in this fresh cold water bath until the desired whiteness is obtained. The cotton is then washed in luke-warm water to take away the acid and cleanse the same.

I find that by my bleaching process, I can take fibrous material (such as cotton, linen or artificial silk) that has already been dyed and obtain a natural whiteness of the material, whereupon the goods may be redyed into any suitable color. I also find that by the use of my bleaching process, the fibers, after bleaching, retain their natural durabllity, not having been in any way weakened or disintegrated, which occurs by the use of other bleaching processes, known to me. Furthermore by my process I perform the bleaching operation in considerably less time than by the processes heretofore in use.

Having now described my invention, what I claim and desire to secure by Letters Patent is:

1. An improved bleaching process which ,consists in treating fibrous material first .-l1'1 a bath containlng permanganate of potassium and sulfuric acid, and thereupon in a bath containing sodium nitrite.

2. An improved bleaching process which consists in treating fibrous material first in a bath containing permanganate of potassium, and thereupon in a bath containing sodium nitrite.

3. An improved bleaching process which consists in treating fibrous material in a bath containing permanganate of potassium and sulfuric acid, and in a separate bath containing a neutralizing agent.

4. An improved bleaching process, which consists in immersing the material to be bleached in a bath containing sodium nitrite; then immersing the material in a bath containing permanganate of potassium and sulfuric acid, and thereupon subjecting the material to a cleansing bath.

5. An improved bleaching process, which consists in immersing the material to be bleached in a cold bath containing about three per cent. permanganate of potassium and about one per cent. of sulfuric acid, proportioned to the weight of said material; thereupon immersing said material in a cold bath containin about two and a half per cent. sodium nitrite and three per cent. of sulfuric acid, proportioned to the weight of said material, and thereupon subjecting the material to a cleansing bath.

Signed at New York city, N. Y. this 8th 7 day of April, 1912.

EUGENE L. MAUPAI. Witnesses:

ABRAM SHLIVEK, ESTELLE O. HAMBURGER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

